FKIE_CVE-2026-55491
Vulnerability from fkie_nvd - Published: 2026-08-20 22:17 - Updated: 2026-10-26 10:10
Severity
Summary
BigBlueButton is an open-source virtual classroom. Prior to 3.0.29, BigBlueButton failed to escape meetingName in record-and-playback/screenshare/playback/index.html.erb when generating the screenshare playback format. A low-privileged user could store a crafted meeting name that embedded script content, and the script executed in another user's browser when that user replayed the recording. This issue is fixed in version 3.0.29.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"product": "bigbluebutton",
"vendor": "bigbluebutton",
"versions": [
{
"status": "affected",
"version": "\u003c 3.0.29"
}
]
}
],
"source": "security-advisories@github.com"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "BigBlueButton is an open-source virtual classroom. Prior to 3.0.29, BigBlueButton failed to escape meetingName in record-and-playback/screenshare/playback/index.html.erb when generating the screenshare playback format. A low-privileged user could store a crafted meeting name that embedded script content, and the script executed in another user\u0027s browser when that user replayed the recording. This issue is fixed in version 3.0.29."
},
{
"lang": "es",
"value": "BigBlueButton es un aula virtual de c\u00f3digo abierto. Antes de la versi\u00f3n 3.0.29, BigBlueButton no logr\u00f3 escapar el nombre de la reuni\u00f3n en record-and-playback/screenshare/playback/index.html.erb al generar el formato de reproducci\u00f3n de la pantalla compartida. Un usuario de bajo privilegio podr\u00eda almacenar un nombre de reuni\u00f3n manipulado que incrustaba contenido de script, y el script se ejecutaba en el navegador de otro usuario cuando ese usuario reproduc\u00eda la grabaci\u00f3n. Este problema est\u00e1 solucionado en la versi\u00f3n 3.0.29."
}
],
"id": "CVE-2026-55491",
"lastModified": "2026-10-26T10:10:00.140",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 5.4,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "LOW",
"integrityImpact": "LOW",
"privilegesRequired": "LOW",
"scope": "CHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N",
"version": "3.1"
},
"exploitabilityScore": 2.3,
"impactScore": 2.7,
"source": "security-advisories@github.com",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-55491",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-08-21T15:49:35.408716Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-08-20T22:17:22.347",
"references": [
{
"source": "security-advisories@github.com",
"url": "https://github.com/bigbluebutton/bigbluebutton/commit/a53f2b92022388bfa4109d3136d1f3a932404b1b"
},
{
"source": "security-advisories@github.com",
"url": "https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.29"
},
{
"source": "security-advisories@github.com",
"url": "https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-57p5-c888-74f9"
}
],
"sourceIdentifier": "security-advisories@github.com",
"vulnStatus": "Deferred",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-79"
}
],
"source": "security-advisories@github.com",
"type": "Secondary"
}
]
}
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Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
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The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
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